题目

AIDS’ Threat to Asia Grows NEW DELHI----Just a few years ago, Mala was a typical middle-class Indian housewife. She cooked, cleaned and looked after her two small children. Last year, her life took a tragic turn. Her husband died of AIDS; she was found out HIV-positive and her mother-in-law took her children away from her, saying they would get the disease. “When friends dropped for a visit, she would introduce me, saying, ‘She is my son’s widow. She has AIDS,’” said Mala. AIDS is now described as “explosive(炸药)” around the world. A study of a hospital in the port city of D水(H2O)在很多化学反应中具有极其重要的作用。请研究下列水参与的氧化还原反应。 ①NaH+H2O=NaOH+H2↑ ②2Na2O2+2H2O=4NaOH+O2↑ ③2Na+2H2O=2NaOH +H2↑ ④3NO2+H2O=2HNO3+NO ⑤2H2O2H2↑+O2↑ ⑥2F2+2H2O=4HF+O2 (1)水只作氧化剂的是___；水只作还原剂的是____； 水既作氧化剂，又作还原剂的是___；水既不作氧化剂，又不是还原剂的是____。 (2)水作氧化剂时，被还原的元素是____，水作还原剂时，被氧化的元素是____。 (3)写出化学方程式②的离子方程式_____ 。